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Cosmic Origins

We inhabit an almost inconceivably vast and ancient universe. Yet our telescopes and theories are able to probe the dawn of time, before the Earth existed, when the observable universe was tiny, hot, and dense.

Cosmic Origins is the story of the universe but it's also our story. Hear about origin of space and time, mass and energy, the atoms in our bodies, the compact objects where matter can end up, and the planets and moons where life may flourish. Modern cosmology includes insights and triumphs, but mysteries remain. Join the six speakers who will explore cosmology’s historical and cultural backdrop to explain the discoveries that speak of our cosmic origins.

At Centennial Hall on the campus of the University of Arizona. Parking is available on a pay per use basis in the Tyndall Avenue Garage. All lectures begin at 7:00 PM and are free to the public. Call 520-621-4090 or go to cos.arizona.edu for more information.

Feb 1 2011

Cosmology: Making Sense of the Universe

Guy Consolmagno SJ, Astronomer and Curator of Meteorites, Vatican Observatory, Castel Gandolfo, Vatican City State Our "cosmology" is the sum of our assumptions and deductions of how the universe behaves. With the advent of modern physics, the term has been appropriated by physicists and astronomers to represent a scientific description of the origin and nature of the physical universe. But cosmologies can also be outlined in ways that don't use physics and astronomy. Indeed, there is continual feedback between prevailing nonscientific assumptions about the universe and the scientific picture, with each influencing the direction of the other. We'll look at a series of historical cosmologies, and discuss the sometimes hidden assumptions that underlie modern astronomy.

Christopher D. Impey, Distinguished Professor, Astronomy/Steward Observatory, The University of Arizona. The scientific story of creation begins 13.7 billion years ago in a circumstance of incredible temperature and density, when all matter and radiation was contained in a region smaller than an atom. The big bang is now a mature theory, with a web of observational evidence supporting it; and the size, shape and age of the universe have been measured with impressive accuracy. This talk will tell the story of how an iota of space-time turned into a vast cold universe of 100 billion galaxies.

Our current cosmological model describes the evolution of the universe from a very early burst of accelerated expansion (known as inflation) a tiny fraction of a second after the beginning, through the assembly of galaxies and large-scale structure shaped by dark matter, to our present epoch where dark energy controls the ultimate fate of the universe. As successful as it is, this model rests upon three mysterious pillars: inflation, dark energy and particle dark matter. All three point to exciting and important new physics that have yet to be revealed and understood – or possibly, to a fatal flaw in the paradigm.

One of the greatest achievements of twentieth-century science is an understanding of the origin of matter. While hydrogen and helium were produced in the Big Bang, the origin of the heavier elements—the silicon in rocks, the iron in our blood, and the oxygen we breathe–lies in the lifecycle of stars. Nuclear reactions, which transform light elements into heavier ones, cause stars to shine and ultimately to explode, seeding the universe with their production. These newly formed elements, the building blocks of ordinary matter, play a central role in the formation of planets and the evolution of life.

Gravity is the most important force in the universe, holding together planetary systems, stars, and galaxies. It is what makes the stars hot enough to shine and what keeps the Earth close enough to the Sun for life to form. It is also what ends the life of every massive star with a spectacular collapse and the formation of a black hole. Finding and studying hundreds of black holes within the Milky Way and in other galaxies brings us closer to understanding gravity at its extreme.

Our reconstruction of the chronology of events that led to the origin of the Earth and subsequent chemical evolution on our planet informs us that nothing unusual was required for the origin and development of terrestrial life, and that therefore life may be pervasive throughout the cosmos. Whether extraterrestrial life exists is so ancient and beguiling a question that humankind is actively seeking the answer in its explorations of the planetary systems in our solar system. It may one day transpire that we discover that genesis has occurred, independently, not once but twice in our solar system. At that point, we could safely infer that life is a fundamental feature of our universe ... along with dark matter, supernovae, and black holes.